DESCRIPTION: The goal of this project is to develop a self-help behavioral intervention to promote smoking reduction among treatment resistant smokers. The program, LifeSign for Smoking Reduction (LS-SR) will be composed of two components: a credit-card sized hand-held computer and a program guide. The computer will structure a scheduled, gradual reduction (SGR) and maintenance protocol that will reduce smoking rate by approximately 50%. The treatment guide will contain instructions for using the computer and standard behavioral strategies to facilitate smoking reduction and relapse prevention. During Phase I, a prototype of the treatment program will be developed and evaluated in a 10-week feasibility study with 100 subjects randomly assigned to receive one of two treatment programs: 1) LS-SR, or 2) a treatment manual for gradual rate reduction. The primary criteria for determining feasibility will be statistically significant differences between groups on reductions in smoking rate and reductions in expired air carbon monoxide. Data on changes in smoking rate throughout treatment, quit attempts, withdrawal symptoms, adherence to the smoking schedule, and program satisfaction will be evaluated. Quantitative results and qualitative feedback from subjects will be used to guide further product development. During Phase II, a second generation prototype computer will be developed and evaluated in a large-scale clinical trial with extended follow-up.